Deprecated is_decade and is_close_to_int

Author: oscargus

doc/api/next_api_changes/deprecations/22268-OG.rst

@@ -0,0 +1,10 @@
+``ticker`` functions deprecated
+-------------------------------
+
+The functions ``matplotlib.ticker.is_decade`` and
+``matplotlib.ticker.is_close_to_int`` are considered internal and public access
+is deprecated.
+
+For ``is_close_to_int`` use ``math.isclose(x, round(x))`` instead.
+For ``is_decade`` use
+``y = numpy.log(x)/numpy.log(base); numpy.isclose(y, numpy.round(y))``

lib/matplotlib/ticker.py

@@ -988,7 +988,7 @@ def __call__(self, x, pos=None):
         b = self._base
         # only label the decades
         fx = math.log(x) / math.log(b)
-        is_x_decade = is_close_to_int(fx)
+        is_x_decade = _is_close_to_int(fx)
         exponent = round(fx) if is_x_decade else np.floor(fx)
         coeff = round(b ** (fx - exponent))
 
@@ -1072,7 +1072,7 @@ def __call__(self, x, pos=None):
 
         # only label the decades
         fx = math.log(x) / math.log(b)
-        is_x_decade = is_close_to_int(fx)
+        is_x_decade = _is_close_to_int(fx)
         exponent = round(fx) if is_x_decade else np.floor(fx)
         coeff = round(b ** (fx - exponent))
         if is_x_decade:
@@ -1108,7 +1108,7 @@ def _non_decade_format(self, sign_string, base, fx, usetex):
         b = float(base)
         exponent = math.floor(fx)
         coeff = b ** (fx - exponent)
-        if is_close_to_int(coeff):
+        if _is_close_to_int(coeff):
             coeff = round(coeff)
         return r'$\mathdefault{%s%g\times%s^{%d}}$' \
             % (sign_string, coeff, base, exponent)
@@ -1212,9 +1212,10 @@ def set_locs(self, locs):
         if not self._minor:
             return None
         if all(
-            is_decade(x, rtol=1e-7)
-            or is_decade(1 - x, rtol=1e-7)
-            or (is_close_to_int(2 * x) and int(np.round(2 * x)) == 1)
+            _is_decade(x, rtol=1e-7)
+            or _is_decade(1 - x, rtol=1e-7)
+            or (_is_close_to_int(2 * x) and
+                int(np.round(2 * x)) == 1)
             for x in locs
         ):
             # minor ticks are subsample from ideal, so no label
@@ -1261,7 +1262,7 @@ def _format_value(self, x, locs, sci_notation=True):
             precision = -np.log10(diff) + exponent
             precision = (
                 int(np.round(precision))
-                if is_close_to_int(precision)
+                if _is_close_to_int(precision)
                 else math.ceil(precision)
             )
             if precision < min_precision:
@@ -1283,13 +1284,13 @@ def __call__(self, x, pos=None):
             return ""
         if x <= 0 or x >= 1:
             return ""
-        if is_close_to_int(2 * x) and round(2 * x) == 1:
+        if _is_close_to_int(2 * x) and round(2 * x) == 1:
             s = self._one_half
-        elif x < 0.5 and is_decade(x, rtol=1e-7):
-            exponent = round(np.log10(x))
+        elif x < 0.5 and _is_decade(x, rtol=1e-7):
+            exponent = round(math.log10(x))
             s = "10^{%d}" % exponent
-        elif x > 0.5 and is_decade(1 - x, rtol=1e-7):
-            exponent = round(np.log10(1 - x))
+        elif x > 0.5 and _is_decade(1 - x, rtol=1e-7):
+            exponent = round(math.log10(1 - x))
             s = self._one_minus("10^{%d}" % exponent)
         elif x < 0.1:
             s = self._format_value(x, self.locs)
@@ -2145,6 +2146,7 @@ def view_limits(self, dmin, dmax):
             return dmin, dmax
 
 
+@_api.deprecated("3.6")
 def is_decade(x, base=10, *, rtol=1e-10):
     if not np.isfinite(x):
         return False
@@ -2154,6 +2156,19 @@ def is_decade(x, base=10, *, rtol=1e-10):
     return is_close_to_int(lx, atol=rtol)
 
 
+def _is_decade(x, *, base=10, rtol=None):
+    """Return True if *x* is an integer power of *base*."""
+    if not np.isfinite(x):
+        return False
+    if x == 0.0:
+        return True
+    lx = np.log(abs(x)) / np.log(base)
+    if rtol is None:
+        return np.isclose(lx, np.round(lx))
+    else:
+        return np.isclose(lx, np.round(lx), rtol=rtol)
+
+
 def _decade_less_equal(x, base):
     """
     Return the largest integer power of *base* that's less or equal to *x*.
@@ -2204,10 +2219,15 @@ def _decade_greater(x, base):
     return greater
 
 
+@_api.deprecated("3.6")
 def is_close_to_int(x, *, atol=1e-10):
     return abs(x - np.round(x)) < atol
 
 
+def _is_close_to_int(x):
+    return math.isclose(x, round(x))
+
+
 class LogLocator(Locator):
     """
     Determine the tick locations for log axes